Kippzonen BSRN Scientific Solar Monitoring System Manuale Utente

WORLD CLIMATE RESEARCH PROGRAMME BASELINE SURFACE RADIATION NETWORK (BSRN) Operations Manual Version 2

VIIIList of FiguresFigure 1.1. Map of BSRN sites...1Figure 3.1. Diagram indicating appropr

88Annex B Selected InstrumentationB 1. Instrument SpecificationsB 1.1 IntroductionThe information found in this annex is based upon the use of particu

Pyranometers, pyrheliometers and pyrradiometers have been categorized into three groupings depending27upon the quality of the instrument. The instrum

90Pyrheliometer Specification ListSpecification Class of PyrheliometerSecondaryStandardFirst Class Second ClassResponse time: time for 95% response &

91B 2. PyranometersB 2.1 Eppley Laboratory Model PSP PyranometerThe Precision Spectral Pyranometer is designed for the measurement of sun and sky radi

92Zero off-seta)response to 200 W m net + 7 W m-2 -2thermal radiation (ventilated)b)response to 5 K h change ± 2 W m-1 -2in ambient temperatureNon-s

93(bubble half out of the ring)Coincident with base of the instrument.Detector surface and base are coplanar within 0.1°Materials Anodized aluminium c

94Spectral selectivity ± 2%percentage deviation of theproduct of spectral absorptanceand spectral transmittance from the corresponding meanwithin 0.35

95Directional response 5 W m-2for beam radiationQuartz domes Infrasil IIB 2.5 Carter-Scott Middleton EP09 PyranometerThe EP09 sensor has an upwards fa

96Signal output (responsivity) 1.00 mV/W m-2Signal resolution < 1.0 W m-2Zero point ( at 20 C ) ± 1.5 W mo-2Zero point temperature coefficient <

97B 2.7 Eppley Black and White Pyranometer (Model 8-48)The Black and White Pyranometer has a detector consisting of a differential thermopile with the

IXFigure D 1.1. The sky functions used in this calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138Figure D 1.

98Linearity < 0.5 % in the range 0.5 to 1330 W m-2Response time < 25 sec. (95%), < 45 sec. (99%)Weight 1.0 kgCable 2-polar shielded, 3 m leng

99B 3. Cavity Radiometers and PyrheliometersB 3.1 Eppley Laboratory HF/AHF Cavity RadiometerThe self-calibrating Absolute Cavity Pyrheliometer has bee

100CONTROL BOX:Size: 7 in. high x 17 in. wide x 16 in. deepW eight: 23 lb (approx)Power requirement: 115 VAC 60 @ or 230 VAC 50 Hz selectableB 3.2 PMO

101Receiver Cavity with inverted cone shaped bottom, coated with specular black paint cavity(absorptance : >.9998).Detector Electrically calibrated

102Linearity ±5% from 0 to 1400 W m-2Response time 1 second (1/e signal)Mechanical vibration tested up to 20 g’s without damageCalibration reference E

103Full opening angle 5° ± 0.2°Slope Angle 1° ± 0.2°Sight accuracy +0.2° from optical axisMaterials Anodised aluminum case, stainless steel screwsWin

104Compact size and light weightWindow is optical sapphire for chemical and scratch resistanceMarine-grade aluminium, hard anodised, for corrosion rsi

105Standby current draw: 0.1 MaStartup settling time: 1.5sTemperature output YSI 44031 thermistor (10kS @ 25 C)oWindow material Optical sapphire, 2mm

106B 4. PyrgeometersB 4.1 Eppley Precision Infrared Radiometer (PIR)This pyrgeometer is a development of the Eppley Precision Spectral Pyranometer. It

107A specially coated silicon dome transmits incoming radiation with wavelength of more than 3 micron, bycutting off shorter wavelengths. The output o

XList of TablesTable 1.1. BSRN Stations ...3Table 1.2. List of site evaluation criteria

108B 5. Sunphotometers and Spectral RadiometersB 5.1 Kipp and Zonen POM-01L Sky RadiometerThe POM-01L Sky Radiometer is a research instrument intended

109Mechanical:Instrument dimension i x L: 89 x 390mmInstrument mass 3 kgControl box dimensions H x L x W: 300 x 250 x 160 mmControl box mass 8.250 kg

110B 5.5 CIMEL Electronique Automatic Sun Tracking Photometer CE 318The CE 318 automatic sun tracking photometer has been designed and realized to be

111Cavity size; CWL tolerance 3-cavity, Ø25 mm; ±2 nmSide-band blocking OD4, UV to 1200 nmDetector type; active area UV si-photodiode; 33 mm2Sensitivi

112Detector tem perature control selection: 30°C, 40°C, 50°C (by jum per on circuit board); stability±0.1 °Cwarm up = 5°C min ; cooling tim e consta

113Annex C The Geometry and Measurement of Diffuse RadiationThis annex provides the report of the BSRN W orking Group on Diffuse Measurements that des

114C 1. Final Report of the Working Group on Solar Diffuse Shading GeometryPrepared by: G. Major and A. OhmuraC 1.1 Terms of reference The Baseline Su

115of integration of the radiation falling on the receiver of the instrument: Ohmura integrates first thedirection of the rays, Major integrates first

116C 2. Annex 1 to Diffuse Geometry WG Report: The effect of diffusometer shading geometryPrepared by G. Major, Z. Nagy and M. Putsay for the BSRN Mee

117Country RmmrmmLmmSlopeangleLimitangleOpeningangleRemarkAustralia I 34.8 10 795 1.79 3.23 2.51 Sky solarAustralia II 34.8 5.64 795 2.10 2.91 2.51 Sk

1Figure 1.1. Map of BSRN sites.Baseline Surface Radiation NetworkOperations Manual(Version 2.1)1.0 IntroductionThe determination of a global clim atol

118Figure C 2.1. Penambra functions of diffusometers for 45 degrees solar elevation.Comparing the calculated and measured sky functions it is seen, th

119Figure C 2.2. Compared log measured and calculated circumsolar functions.Letters A, B, C, D, E, F symbolizes different aerosol models.Summarizing t

120Figure C 2.3. Measured sky functions and their approximations by onescalculated for model atmosphere containing rural aerosol and haze particles. D

121Pyrheliometer Direct radiation Circum 1 Circum 2 “Measured”CRO3 770 2.92 7.74 780.7ABS 770 3.05 8.04 781.1KIPP 770 3.11 8.65 781.8NIP 770 3.11 10.9

122Figure C 2.5. Dependence of the HUNI/HUNIII on direct radiation.C 2.4 Reduction of measurements to standard geometryThe empirical formulae in sect

123(4) Using the empirical formulae mentioned in (1) and (2) the diffuse radiation measured by a diffusometercould be corrected to standard geometry.

124C 3. Annex 2 to the Diffuse Geometry WG Report: Optimization of Diffusometers to PyrheliometersPrepared by G. Major and M. Putsay,Hungarian Meteo

125measurement, namely the atmospheric conditions (scattering) and the solar elevation. For a givenpyrheliometer and given circumstances several such

126C 3.2.2 The pyrheliometers and pyranometersFor several pyrheliometers the basic geometric data can be found in (Major 1995). From these, threeins

127the diffusometer has been fitted to the pyrheliometer. Table C 3.4 provides information on the originallength of the diffusometer arm and the optim

2implementation documentation. Whether a site is new or has been in operation for many years,operators and scientists can learn from each other to imp

128Pyranometer Radius of shadingdisk/sphereArm lengthto fit to HFArm lengthto fit to CH-1Arm lengthto fit to NIPCM 11 or 21 25.4 630 603 505EPPLEY PS

129Figure C 4.1. Measured sky functions and their approximations by onescalculated for model atmosphere containing rural aerosol and haze particles to

130Figure C 4.2. Relationship between the geometry ofpyrheliometers and radiance (The relationshipapplies for a diffusometer when the sun is at zenith

131Figure C 4.3a. Relationship between the shadow discand the sensor of a pyranometer.Figure C 4.3b. Detail of the sensor projectionon to the normal p

132Pyrheliometer and Diffuse Geometry ConfigurationsACR or Kipp &Zonen CH1Kipp & Zonen 2APTracker with CMseries pyranometerEppleySDKBSRN with

133The integration of Fr' for the entire sensor surface gives,Then,Likewise for the sun at an arbitrary zenith angle q, we obtain the followings:

134phSince the irradiance on the surface by a pyrheliometer adjusted for the horizontal surface F isthe following relation must be kept,where the sub

135Annex D Pyrheliometers and PointingD 1. On the Pointing Error of PyrheliometersPrepared by G. Major for the BSRN discussion held in Davos, Switzerl

136If the optical axis of the pyrheliometer is not directed to the solar centre, than the angle measured fromthe solar centre (z1) differs from the an

137(2) If the pointing error of a pyrheliometer is larger than its slope angle, the irradiance of thepyrheliometric sensor decreases rapidly with incr

Location of Operating and Planned BSRN StationsSymbol Station Name Sponsor Latitude Longitude Status3CAM Camborne Great Britain 50/ 13' N 5 / 19&

138Figure D 1.1. The sky functions used in this calculation.Figure D 1.2. The contribution of the solar disk to the irradiance of pyrheliometricsensor

139Figure D 1.4. The contribution of the circumsolar sky to the irradiance ofpyrheliometric sensors. The upper 3 curves belong to the case of continen

140D 2. Effect of Clouds on the Pyrheliometric MeasurementsPrepared by G. Major for the BSRN Workshop held in Boulder, Co, 12-16 Aug. 1996D 2.1 Introd

141Using the data of Figure D 2.1where the constant has to be determined to calculate absolute radiance values.D 2.2.2 Cloud side reflectanceFigure

142The cloud radiances have been tuned to the measured ones, while the cloudless parts are the sameas calculated for the atmospheric column containing

143Figure D 2.2. The geometry of cloud edge scattering.Figure D 2.1. Surface Irradiance: the shadow of the model cloud.

144Figure D 2.3. The geometry of cloud side reflectance.

145Figure D 2.4. Measured radiance functions: example for the cloud sidereflectance (upper curve) as well the clearest cases for high and low solarele

146Figure D 2.7. Model radiances for the cloud edge scattering and for the clearsky, mountain aerosol, h=60 degrees.Figure D 2.6. Model radiances of c

147Figure D 2.9. The basic geometrical characteristics of the pyrheliometersinvolved into the calculation.Figure D 2.8. Model radiances for the cloud

4• how will the data be quality controlled and archived?In the BSRN, standards of measurement accuracy and archiving have been clearly defined, butthe

148Figure D 2.10. Cloud effect for the ABS pyrheliometer group.Figure D 2.11. Cloud effect for the Crommelynck 3L pyrheliometer.

149Figure D 2.13. Cloud effect for the NIP pyrheliometer.Figure D 2.12. Cloud effect for the KIPP pyrheliometer.

150Annex E Suppliers of Solar Tracking Instruments (Partial Listing)BrusagChapfwiesenstrasse 14CH-8712 StäfaSwitzerlandhttp://www.brusag.ch/Eppley Lab

151Annex F Suppliers of Data Acquisition Systems (Partial Listing)F 1. Data Acquisition TypesAlthough the requirements for observing the basic radiati

152Specification Type 1 Type 2 Type 3Analog-to-digitalconverter typeIntegrating Integrating, Sigma-delta or SuccessiveapproximationSuccessiveapproxima

153Data Translation Inc.100 Locke DriveMarlboro, MA 01752-1192USAhttp://www.datx.com/Type 3EIS Pty LtdP.O. Box 281Roseville, NSW 2069Australiahttp://w

154Annex G Sample log sheetsThe primary reason for keeping a log of the activities about the station is to help in determining thequality of the data.

155Figure G 1. Sample log sheet from the University of Calgary.

156Figure G 2. Sample log sheet from the NREL HBCU solar radiation network.

157Figure G 3. Sample log sheet from the Canadian BSRN site.

5• experts intending to obtain the necessary resources to establish a BSRN station• technologists involved in the construction and operation of a BSRN

158Annex H Common Terms and Formulas used in Uncertainty DeterminationsThe terms and definitions reproduced below are based on those in Guide to the E

159viii. approximations and assumptions incorporated in the measurement method and procedureix. variations in repeated observations of the measurand u

160Notes:a. The value of a quantity may be positive, negative or zero.b. The value of a quantity m ay be expressed in more than one way.c. The values

161Influence quantityQuantity that is not the measurand but that affects the result of the measurement.Result of MeasurementValue attributed to a meas

162Experimental standard deviationFor a series of n measurements of the same measurand, the quantity characterizing the dispersionof the results and

163b. Because only a finite number of measurements can be made, it is possible to determine onlyan estimate of random error.Systematic errorMean that

164H 2. Common FormulasH 2.1 Type A EvaluationIf the number of measurements is , and is the i measurement then: thMeanVarianceStandard DeviationExpe

165Rectangular DistributionIf the semi-range is , then the standard uncertainty, , is given by:The degrees of freedom (v) for a rectangular distribu

166Annex I Solar Position AlgorithmAn algorithm is provided for the calculation of astronomical parameters in QuickBasic. The subroutineis based upon

167Subroutine Solar: Equations based upon the paper of Michalsky (1988) and the approximate equationsgiven in the Astronomical Almanac.Note: Subroutin

6• Extended-Surface Reflectance and In Situ Measurements: development of methods formeasuring surface reflectance over a larger area (e.g., 20 X 20 km

168' MOD(X,Y) = X (MOD Y) = X - INT(X / Y) * Y' The INT function in Fortran is identical to that in QuickBasic;'

169 HC1 = .0001184#' Constant for the calculation of airmass AC1 = -1.253#' Get the current julian date (actually add 2,400,000 for JD).

170' Calculate hour angle in radians between -Pi and Pi. Ha = LMST - Ra IF Ha < -pi THEN Ha = Ha + TwoPi IF Ha > pi THEN Ha = Ha - Tw

171 SolarMn$ = RIGHT$(STR$(SMn), 2) IF ABS(SMn) < Ten THEN SolarMn$ = "0" + RIGHT$(STR$(SMn), 1) SolarSc$ = RIGHT$(STR$(SSc), 2)

172Figure J 1. A BSRN station and the WRMC.Annex J BSRN Data ManagementThis annex contains an outline of the BSRN data management. A comprehensive d

173All data in the BSRN database are consistent. The radiation data however may be afflicted with error,though their quality was controlled by the sta

174IndexAerosol Optical Depth ... III, 53- 56, 58, 108, 114airmass ...

175Instrument Platform ...15, 24, 26, 28, 31Instrumentsabsolute cavity radiometer ...

176Shade... 11, 25, 33-35, 37, 66, 68, 113Signal Cable ...

7upgrading older networks can also benefit from results of the ongoing research conductedspecifically to improve the measurement of solar and terrest

82.0 Sampling Frequency and Accuracy Requirements for BSRN Stations2.1 Sampling Frequency2.1.1 Sampling Frequency of Radiation MeasurementsThe BSRN re

Uncertainty is defined as a parameter associated with the result of a measurement, that characterizes the1dispersion of the values that could reasonab

10BSRN Measurement UncertaintyQuantity 1991* 1997 Target** 2004 Target†1. Direct Solar Irradiance 1% or 2 W m 0.5% or 1.5 W m-2 -22. Diffuse Radiation

Major, G., 1992: Estimation of the error caused by the circumsolar radiation when measuring global4radiation as a sum of direct and diffuse radiatio

Alados-Arboledas, L., J. Vida and J.I. Jiméniz, 1988: Effects of solar radiation on the performance of6pyrgeometers with silicon domes. Jour. Atmos.

Philipona, R., E.G. Dutton, T. Stoffel, J. Michalsky, I.Reda, A. Stifter, P. W endling, N. W ood, S.A. Clough,8E. J. Mlawer, G. Anderson, H.E. Reverco

14better than one second, this time accuracy was relaxed to one second at the BSRN Science andReview Workshop (Boulder, Colorado, USA, 12-16 August, 1

Three locations where further information on time synchronization can be found are: 9(1) NIST: http://www.boulder.nist.gov/timefreq/service/its.htm (

163.0 The BSRN Site3.1 Geographic Location of Site3.1.1 General ConsiderationsIn selecting sites for the Baseline Surface Radiation Network, the obje

17(6) near vehicle parking areas; and(7) where heat is exhausted by vehicles or buildings.Conversely, BSRN stations must be located where facilities e

IAcknowledgementsThe efforts required in creating any document far exceed the capabilities of any one person. This manual hasbeen no exception. I woul

18In locations where a site is presently located, this information should be present with the requiredaccuracy.Global Positioning System (GPS) technol

19The description consists of 11 sections broken down into three main areas: General Description,Site Description and Station Description; m uch of t

20Data in relation surface typeValue Major Surface Type Descriptor1 glacier accumulation area2 glacier ablation area3 iceshelf -4 sea ice -5 water riv

213.3 Instrument ExposureTo obtain data on the radiative field with respect to the surroundings, it is necessary to map thehorizon of the instrument.

22power available. This can be accomplished by obtaining information on the power supply from thelocal power authority.The minimum suggested protectio

Stamper, D.A., 1989: Business Data Communications, 2 Edition, Benjamin/Cummings Publishing Co.nd10Ltd., Redwood, CA, U.S.A.23The Wide Area Network is

24data. While it is impossible to have complete defence against loss, the needfor security must be balanced against the cost of its implementation.Dis

AES Guidlines for Co-operative Climatological Autostations, Version 2.0, Climate Information Branch,11Canadian Climate Service, Atmospheric Environmen

26Figure 3.2. Simple post mount in concrete base.least affects the data. In the case of a wind mast, the mast should be placed where theobstruction al

27Figure 3.3. The support structure used to elevate instruments above thelocal horizon. The structural steel and concrete support structure at theBrat

IIPreface to the First EditionLike all aspects of the Baseline Surface Radiation Network, this manual is in its infancy. The ideas containedwithin may

28A number of dataloggers are capable of withstanding harsh environments, including hot andcold temperatures and high relative humidity. Such data col

Figure 3.4 Generalized schematic of the interface between radiation sensors (RF) and a data acquisition unit showing lightning protection and cablegro

304.0 Installation of Radiation Instruments4.1 GeneralThe installation of pyranometers, pyrheliometers and pyrgeometers is relatively simple (Annex B

31(iv) the directional responsivity of the instrument (cosine and azimuthal response of theinstrument) for pyranometers(v) the deviation of the temper

32Figure 4.1. Ventilator with motor located beside the instrument as used by DeutscherWetterdienst.Spring loaded bolting devices for mounting the inst

33Figure 4.2. Ventilator with the motor locatedbeneath the instrument. Note the extraventilation holes near the top of the housingused to reduce sno

34Figure 4.3. An one-axis tracker used in shading apyranom eter. Note the use of two fine wires to m aintainthe stability of the shading disk. (Develo

35(2) The synchronous motor must:(I) be wired appropriately the electrical power frequency of the location of installation,(ii) be wired to follow the

Major, G., 1992: Estimation of the error caused by the circumsolar radiation when measuring global12radiation as a sum of direct and diffuse radiation

37Pyranometer Radius ofshadingdisk/sphereArm lengthrequired forEppley HFArm lengthrequired forEppley NIPArm lengthrequired forKipp andZonen CH1Eppley

IIIPreface to the Second EditionThe World Climate Research Programme (WCRP) Baseline Surface Radiation Network (BSRN) has beenoperating as a network o

38Figure 4.6. Canadian computer-controlled, friction-drive tracker usedfor measuring direct beam, diffuse and infrared radiation using ashaded pyrgeom

39This method works well if the instrument is on a vertical post attached to the boom extendingfrom the tower. The pyranometer is levelled while the p

40(iii) the deviation of the temperature compensation circuit of the instrument over thetemperature range (-10° to +10° of the local range in tempera

41instructions for each of these devices. A broad overview, however, is important because of the significancesolar tracking plays in the measurement o

42Figure 4.9. Brusag two-axis active tracker. Activetracking is accomplished by balancing the signals fromthe quadrant sensor that is found on the fl

43Types of Solar Pointing Devices Used in the BSRNTracker Type Advantages DisadvantagesSynchronous Motor(Equatorial Mount)Figure 4.8- least expensive-

445.0 Data Acquisition5.1 IntroductionInstalling and maintaining the network data acquisition system(s) is crucial if consistent high qualityradiation

45Of secondary importance in the selection of the DAS is its programmability. While the minimum requirementfor the DAS is to measure a set of signals

46to a fault in the system by performing the same zero test with the resistor attacheddirectly to the input terminal of the unit. Servicing by authori

476.0 Maintenance6.1 IntroductionHigh quality, consistent on-site maintenance is crucial if accurate long-term records are to be obtained.Not only doe

IVTable of ContentsAcknowledgements... IPreface to the First Edition ...

48the radiometer dome by sand or by hyrdometeorites such as hail. If the dome is damaged,it should be replaced with one made of the same optical mater

49(ii) Two-axes passive solar trackerPassive trackers use either internal or external computers to calculate the position ofthe solar disk. Following

50- for friction-driven drives check for slippage of the drive disks (see tracker operatingmanual for the proper procedure).- if slippage occurs on ge

516.3 Weekly MaintenanceThe minimum weekly requirements for maintaining a BSRN radiation station are as follows (in additionto the daily maintenance):

526.4.2 Annual maintenanceIdeally, the annual m aintenance should take less than one day to complete if a team of workers ispresent. Although unlikel

Holben, B.N., T.F.Eck, I. Slutsker, D. Tanré, J.P. Buis, A. Setzer, E. Vermote, J.A. Reagan, Y.J. Kaufman,13T. Nakajima, F. Lavenu, I Jankowiak, and A

54AOD values obtained from the archive would continue to be based solely on the submitted transmissiondata.7.2 Instrument and Wavelength Specification

55Table 7.1 lists the BSRN wavelengths, maximum displacement from the nominal wavelength and themaximum waveband (Full Width at Half Maximum) in order

56original filters and from the same manufacturing lot. In this manner, the waveband characteristics canbe maintained over longer periods of time. 7.3

57(2) A series of 20 or more ‘Langley’ type calibrations at a high transmission site over a periodof three months or less.(3) An absolute calibration

V4.2.3 Mechanical installation of shaded sensors (pyranometers and pyrgeometers)... 334.3

Forgan, B.W ., 1986: Determination of aerosol optical depth at a sea level station - investigations at Gape16Grimm BAPS. CGBAPS Technical Report 5. Ga

Forgan, B.W., 1988: Sun photometer calibrations by the ratio-Langely method. In Bas elien Atmospheric18Program (Australis) 1986, edited by B.W . Forag

607.4.2.3 Objective AlgorithmThe objective algorithm described by Harrison and Michalsky provides a means to remove observations5that may contaminate

61The use of a standard lamp either as a calibration source or as an irradiance source for use with adetector standard, requires precision measurement

62Devices that use diffusers should also be cleaned daily by gently brushing debris from the diffusermaterial. If the diffuser is extremely dirty, dis

63Field Parameter Description Explanation1 Number of Instruments numeric value of number ofinstruments supplying datamore than one instrument may be s

Philipona, R. C.Frööh, K. Dehne, J. DeLuisi, J. Augustine, E. Dutton, D. Nelson, B. Forgan, P. Novotny, J.19Hickey, S.P. Love, S.B. Bener, B. McArthur

65to guard against performance degradation between international comparisons. One means of monitoringperformance is the use of the reference instrumen

Forgan, B. W ., 1996: A new method for calibrating reference and field pyranometers, Journal of21Atmospheric and Oceanic Technology, 13 638 - 645.66

67Secondly, it alleviates the potential of thermal shock to the instrument which occurs first when theinstrument is exposed to direct beam radiation

VI9.3.2 Procedures for specific fluxes ...739.3.2.1 Direct, diffuse and global ...

68To maintain the traceability of pyrgeometer measurements the following procedure has been established:(1) Each BSRN station requires a minimum of tw

69Figure 8.1. Percentage change in infrared flux due to case thermistor errors.Using these values, the difference between the measured temperature at

For example: International Pyrheliometer Comparisons IPC VII, 24 September to 12 October 1990,22Results and Symposium. Working Report No. 162, Swiss M

Dutton, E.G., J.J. Michalsky, T. Stoffel, B.W . Forgan, J. Hickey, D. W . Nelson, T.L. Alberta and I. Reda,232001: Measurement of broadband diffuse so

72= pyrgeometer body temperature (K)= pyrgeometer dome temperature (K)= the electrical output from the thermopile= a correction factor for infrared ir

73considered in these cases. The first is the normal range of the instrument, for example a pyranometerrange may be -0.1 to 12 mV, while the second is

Gilgen, H. et al: Technical Plan for BSRN Data Management, W orld Radiation Monitoring Centre (WRMC)26Technical Report 1, Version 2.1. World Climate R

75Annex A Site Description DocumentationTemplates for use with the site description documentation that is found in Section 3.2.

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VIIC 3. Annex 2 to the Diffuse Geometry WG Report: Optimization of Diffusometers toPyrheliometers ...

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81A.1 Example of Site Description DocumentationThe following pages provide sample pages of the Site Description Docum entation for the Bratt’s Lake Ob

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